yep Hi-Flow cats are better flowing cats that are better on the performance end, and sound end. They volume it up and doesn't sound as awful as running no cats does. While also doing its job at filtering, and keeping the CEL off.

thanks for the compliment. I would have kept it if I had more use for it, but it was just a daily driver, and I didn't want a 11mpg/$400 a month in gas daily driver so I got rid of that thing. Much happier with a Ford truck anyways. That 6.0L did sound good though.